Vehicles, such as motor vehicles, typically contain foot-actuated devices or pedals for controlling various functions of the vehicle. These functions are known to include: acceleration, controlled by an accelerator pedal; braking, controlled by a brake pedal; and shifting, controlled by a clutch pedal. In addition, the vehicle may include a non-functional pedal that serves as a footrest for the driver. The pedals are aligned in a predetermined dimensional relationship relative to each other and fixed portions of the vehicle, including the vehicle dash panel, floor, seat and instrument panel. The pedal pad portion of the pedal assembly travels in a predetermined path. In the past, the path was typically an arc. Thus, to move the pedal pad closer to the driver, the pedal pad typically moves along the path into the vehicle, closer to the driver. The pedal pad is moved away from the driver by moving the pedal pad along the path away from the driver.
The pedals are positioned in the vehicle so that they are accessible by the driver. However, drivers come in a wide variety of shapes and sizes, and a pedal positioned to accommodate a large driver with a large foot will generally be unreachable by a small driver with a small foot. In the past, the pedals were fixedly positioned so that the majority of drivers were accommodated, from a functional and ergonomic aspect. An example of a functional aspect of the pedal is the ability of the driver to reach and actuate the pedal. An example of an ergonomic aspect of the pedal is the driver's comfort while actuating the pedal, as measured by a parameter such as foot angle.
More recently, adjustable pedals have been used in vehicles to accommodate a greater number of drivers from a functional and ergonomic perspective. With an adjustable pedal, the driver can modify the position of the pedal so that it is either closer to the driver or away from the driver. However, moving the pedal closer to the driver raises the height of the pedal pad with respect to the floor of the vehicle. As a result, the driver's heel may not rest on the floor of the vehicle. One consequence of not resting the driver's foot on the floor is the potential for foot fatigue during driving. In the past, the length of the accelerator pedal pad was increased to overcome this concern. However, there are limitations as to how much the pedal pad can increase in length. At the same time, it is essential that the relative dimensional relationships between the pedals are maintained during adjustment, such as the height relationship between each of the pedals.
An example of such an adjustable pedal is disclosed in commonly assigned U.S. Pat. No. 6,151,986 to KSR International, Inc. entitled “Adjustable Vehicle Control Pedals,” the disclosure of which is incorporated herein by reference. This type of adjustable pedal works well, and includes an adjustment mechanism comprising a motor, a drive mechanism operatively connected to the motor and a screw mechanism operatively connected to the pedal.
Another example of an adjustable control vehicle pedal is disclosed in U.S. Pat. No. 6,389,927. The patent discloses a control pedal arrangement including a base member having an integral support arm for supporting a pedal arm. The base also has a guide device and control mechanism for adjusting the position of the pedal arm. The control mechanism includes a motor with a gear for driving a screw rod. The screw rod extends between the base and the pedal arm and pivotally adjusts the position of the pedal arm with respect to the operator. In operation, as the pedal arm is pivoted about a pivot axis, the pedal pad moves through an arc which raises the pedal pad as it moves into the vehicle. At the same time the pedal pad is angled upwardly. While this adjustment method works, the modified angle of the pedal pad may not be ergonomically desirable.
Thus, there is a need in the art for an ergonomically beneficial adjustable pedal assembly that controls the rise, run and angle of the pedal pad with respect to the driver during adjustment of the pedal assembly.